This invention relates to ultraviolet curable coating compositions. More particularly, this invention relates to ultraviolet coating compositions having improved cure rates.
Ultraviolet curable coating compositions have for several reasons required the use of large amounts of photoinitiators in typical formulations. These initiators are expensive and difficult to handle and are often insoluble in the final cured coating, or impart to it undesirable colors.
When the amounts of these photoinitiators are lowered to more desirable levels to reduce costs, color, and insolubility, the cure rate of the resulting compositions is greatly reduced. It is theorized that reduced curing is caused by insipient molecular oxygen which tends to retard the ultraviolet curing mechanism.
Thus, it is an object of this invention to prepare ultraviolet curable coating compositions.
It is another object of this invention to prepare coating compositions which utilize lower-than-normal amounts of ultraviolet photoinitiators.
It is another object of this invention to prepare ultraviolet curable coating compositions which are inexpensive and lightly colored.
These and other objectives are obtained by preparing the compositions of the instant invention.